The CAS Registry Mumber 93040-96-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 9,3,0,4 and 0 respectively; the second part has 2 digits, 9 and 6 respectively. Calculate Digit Verification of CAS Registry Number 93040-96: (7*9)+(6*3)+(5*0)+(4*4)+(3*0)+(2*9)+(1*6)=121 121 % 10 = 1 So 93040-96-1 is a valid CAS Registry Number.